The social representation of the mangrove in Mayotte Island

International audienceContrary to mangrove research in natural sciences, studies on the interaction between societies and mangroves are quite recent, appearing slowly in the 1980s. Part of the social studies on mangroves has been done by natural scientists, noticing the knowledge gap. It partially explains why the social research on the mangroves has seldom used concepts or theory applied by social scientists to other ecosystems (e.g. coral reef, sea) such as local ecological knowledge or social representation theory (SRT). SRT emerged in France in the 1960s, through the intersection of sociological and psychological research, and spread worldwide and through disciplines over the following decades. SRT considered that some objects become “social” when they create a system of opinions, beliefs and knowledge socially elaborated and distributed on them. They can explain and orient practices and define the identity of an individual or a group, creating a feeling of belonging. Studies on the social object “nature” found that its social representation (SR) is built on three dimensions: 1. the cognitive dimension based on knowledge and belief on the object; 2. the normative dimension that translates the values applied to the object inducing and justifying behaviours; 3. the expressive dimension showing the sensible and emotional relationship that the object provokes. People justify their actions or wishes on nature based on their value, that can be built from the same system of knowledge, belief and sensibility. Better understanding the SR of the mangrove by a society helps to understand what can be implemented easily from a management plan and which points would need more discussion and compromise with the inhabitants.In the Mozambique Channel, Mayotte island (374 km2) is part of the Comoros Archipelago and a French department since 2011. In 2016, mangroves occupied a surface of 694 ha and 29% of the coastline. Several villages are built just next to a mangrove, so that 14 of the 17 municipalities having a mangrove along their coastline. The back mangroves and sometimes part of the internal mangroves are settled by slums. Out of the 256,000 inhabitants reported in 2017, almost half of the population has a foreign nationality, 95% of them being Comorians and two-thirds living in slum houses. This study focused on the mangroves of Dembéni and Bandrélé located on the eastern coast of Mayotte in two different municipalities. These fringing mangroves cover 44 ha and 36 ha, respectively, and are relatively stable since 1950. They are bordered by three villages, Dembeni, Iloni and Bandrele, each one presenting a slum neighbourhood close to the mangrove, the one of Iloni being the largest. To assess the SR of the mangrove, we conducted an exploratory survey (because of the lack of previous studies) followed by two main interview and questionnaire campaigns. The semi-structured interviews were conducted with 49 villagers from the three villages in 2018. The questionnaire was administered in 2019 to 7% of those aged over 15 years inhabiting the three villages, representing 439 people. A representative sample was obtained by quota sampling based on information from the 2012 national census about gender, age group and main activity. These two survey campaigns aimed to better understand local knowledge, practices and SR of inhabitants of Mayotte.The questionnaire included a free listing question on the mangrove. For the respondents, the most associated words to the mangrove of their village were “protection”, “rubbish”, “beautiful”, “mangrove trees”, “sea”, “crab” and “fish”. When we specifically asked what surveyed respondents liked about the mangrove of their village, the most frequent answers were the protection from coastal hazards, the landscape, the freshness, the tranquillity and watching trees. When we asked what they did not like, 58% of inhabitants mentioned rubbish. The semi-structured interviews helped better understand the mental schemes of surveyed respondents. The positive attributes of the cognitive dimension of the SR of the mangrove are the services given by the ecosystem as the protection against coastal hazard, the freshness and quality of the air, a habitat for animals. Interviewees also enjoyed the calm of the mangrove, having friendly moments and appreciated the beauty of this ecosystem. Some negative attributes are also associated with the mangrove, such as the increase of rubbish, the insalubrity, the pollution giving illnesses, the silting, the diminishing of marine food and the State control. Moreover, many interviewees believe that the mangrove is home to the spirit mwanaissa, some people being afraid of the mangrove at night and other making offerings. Three values relate to the normative dimension: a functional one, the mangrove providing services to humans; an esthetical one, inhabitants enjoying the view of the mangrove; a spiritual one as a mystic place. It is a society giving mainly anthropocentric values at the mangrove. The expressive dimension presents both positive emotions, such as the pleasure and well-being procured by the mangrove, and negative ones, such as an aversion because of rubbish, waste water and migrants or fear of spirits. It is important to take into consideration for management decisions on what elements are build this social representation of the mangrove. For instance, people disagree with rubbish on mangroves but not with rubbish from making offering. Does the management preserve mangrove from this small quantity of rubbish from offering or integrate it as a cultural aspect of the relationship of inhabitants to the mangrove? Moreover, the positive SR of the mangrove as an ecosystem useful for humans in different ways has been diminishing over the last decades because of the increasing of rubbish and waste water. But it is also a driving force for the moment, stakeholders can rely on inhabitants for their actions of protection and cleaning of the mangrove